In recent years, attention has focused on technology for forming fine patterns such as an electrical wire pattern and mask pattern on the substrate, by using a liquid ejection head (inkjet head) based on an inkjet method. For example, by ejecting droplets of liquid in which metal particles or resin particles are dispersed, from an inkjet head so as to place the droplets on a substrate, a pattern image is formed on a substrate by the liquid, and this pattern is cured by heating or the like, thereby forming an electric wire pattern or a mask pattern. An issue involved in the pattern image forming using the inkjet method is blurring of the ink due to the occurrence of bulging (clumping) which arises when a plurality of droplets deposited on a substrate combine together, and due to the occurrence of jagged edges caused by deviation in the direction of flight of the droplets or movement of the droplets which have been deposited on the substrate.
FIGS. 31A and 31B are diagrams illustrating problems of a fine pattern forming method which uses the inkjet method in the related art, and depict a pattern forming surface 1A of a substrate 1. FIG. 31A shows a state where a plurality of droplets 2 that have been deposited on the pattern forming surface 1A of the substrate 1 have combined together to form one large droplet 3 (a state in which a bulge has occurred). On the other hand, FIG. 31B shows a state where deviation of the landing positions occurs in the droplets 2 deposited on the pattern forming surface 1A of the substrate 1, and hence jaggedness has occurred. In each of FIGS. 31A and 31B, the pattern that originally ought to be formed is indicated by dashed lines denoted with reference numeral 4. Various investigations have been carried out in order to resolve these problems.
NPTL 1 discloses technology for forming an accurate fine pattern image by placing droplets on the substrate by using an inkjet method, after partially changing the surface energy of the substrate through the use of photolithographic technology.
PTL 1 discloses a liquid ejection apparatus which is composed in such a manner that droplets are ejected toward a region surrounded by laser light, whereby droplets which leave a prescribed path of travel are returned to the prescribed path of travel and hence droplets are deposited within the region surrounded by the laser light.
PTL 2 discloses a method in which a solution containing a functional material is sprayed by an inkjet method, thereby leaving the functional material on a base body and hence manufacturing a functional base body. In the technology disclosed in PTL 2, a composition is adopted in which a base body is irradiated with laser light before spraying the solution of the functional material, in such a manner that the adhesiveness of the solution on the base body is improved. PTL 2 further discloses that the size of a single dot (which has a diameter of 15 μm) is larger than the spot size of laser light (which has a diameter of 10 μm).